The present invention relates generally to the performance and athletic potential of horses. In particular, the present invention relates to a method or procedure to predict racing performance in a racehorse by measuring expiratory and inspiratory times during exercise. Most particularly, the present invention relates to a method of predicting racing performance by measuring expiratory and inspiratory times in galloping Thoroughbred racehorses.
Literally for centuries man has sought the ability to predict athletic potential in performance animals. In particular, in the xe2x80x9csport of kingsxe2x80x9d (horse racing) horsemen are constantly in search of the superior racehorse and, accordingly, a consistent and reliable method to enable one to select the superior individual. There are numerous subjective factors to consider when evaluating an animal for future potential as a racehorse including, but not limited to e.g., pedigree, conformation and gait analysis, and the interrelationships thereof.
Oftentimes young horses are sold by commercial breeders or pinhookers and the like as future racing prospects. Would be owners frequently employ the services of individuals or xe2x80x9cexpertsxe2x80x9d (e.g., bloodstock agents) who specialize in their ability to select the superior individual. Given the enormous investment in time and money that is necessary to prepare and maintain a racing animal, e.g., a Thoroughbred racehorse or a racing Quarter Horse, horsemen are constantly in search of a reliable and reproducible and more objective method for selection of the potentially superior racing animal.
Many methods have been tried which utilize both phenotypic as well as genotypic characteristics, including, e.g., measuring the long bones of the distal extremities, measuring the size of the heart, measurement and anatomical consideration of the upper airway, dosage analysis of pedigree and the like. Although certain of these methods and/or various combinations thereof have found some degree of success, to date, there has not been a very consistent, reliable and reproducible system developed for analysis of athletic potential, especially wherein the method of analysis directly relates phenotypic characteristics, e.g., anatomy and/or biomechanical efficiency to the animal""s ability to breathe during performance. Accordingly, there exists a need in the art for such a system.
It is generally known that, at the gallop, a horse must breathe in rhythm with his stride. The normal horse will usually take one breath with each stride and will normally breathe out or exhale only when his/her front legs are on the ground (i.e., during his/her front leg stance time). Prior to the present invention, however, the relationship between the horse""s breathing duration (inspiratory and expiratory time) and the limitations thereof as a function of forelimb anatomy and front leg stance time and/or stance distance during exercise had not been examined.
In the 1980""s D. P. Attenburrow et al. developed a device for recording sound over the trachea which included a radio stethoscope and a spectrogram analysis of inspiratory and expiratory sounds of exercising horses. Later, however, it was found that sounds recorded in such a manner do not necessarily directly relate to the respiratory sounds of the exercising horse, see, e.g., Derksen et al. xe2x80x9cSpectrogram Analysis of Respiratory Sounds in Exercising Horsesxe2x80x9d, AAEP Proceedings, Vol. 45, pp.314-15 (1999) (Incorporated herein by reference). See also, xe2x80x9cSpectrum analysis of respiratory sounds in exercising horses with experimentally induced laryngeal hemiplegia or dorsal displacement of the soft palatexe2x80x9d, AVJR Vol 62, No. 5, pp 659-664 (May 2001).
Derksen et al. advocate the use of a large and cumbersome recording device which can be placed alongside a horse exercising on a treadmill to pick up normal as well as abnormal respiratory sounds and assess pathology of the upper airway based upon the sound patterns produced during exercise, e.g., for detection of laryngeal hemiplegia and dorsal displacement of the soft palate. Derksen""s analytical system, however, is limited in that it cannot be used on a galloping horse under field conditions (e.g., on a horse carrying an exercise rider or jockey and e.g., breezing or working) on a training track. Moreover, Derksen et al. did not examine or disclose any relationship between breathing duration, stance time and speed (velocity) and its effects on athletic potential or performance in the racing animal. Thus, there still exists a need in the art for a device and method which enables analysis of such parameters in the equine athlete, especially under field conditions.
Prior to the present invention, there has been no relationship established between front leg (or forelimb) stance time (or stance distance), speed (velocity), inspiratory and expiratory times and stamina (e.g., involuntary fatigue) which would be useful in predicting racing performance. Accordingly there still exists a need in the art for a method for predicting racing performance in racehorses which utilizes such factors.
It is an object of the invention to provide a method for predicting racing performance and/or identify performance limitations in a horse, e.g., a Thoroughbred, Arabian, Standardbred, Quarter Horse, Racing Paint and the like by measuring expiratory and/or inspiratory times during exercise.
It is also an object of the invention to provide a method for establishing the relationship between measured expiratory and/or inspiratory times during exercise to front leg stance time or stance distance and/or velocity in the prediction of racing performance in a racehorse.
A further object of the invention is to provide a consistent, reliable and reproducible method for determining that special or substantially ideal xe2x80x9cspeedxe2x80x9d (maximum comfortable velocity) at which a particular horse can both run and still breath sufficiently and thereby delay the onset of involuntary fatigue (e.g., fatigue induced via hypoxia and/or lactic acidosis).
Yet another object of the invention is to provide a method for relating the anatomical constraints (the anatomy and/or conformation) of a particular individual horse""s forelimb (e.g., a Thoroughbred horse) to that horse""s available forelimb stance time or forelimb stance distance and further relate such information to that special or substantially ideal xe2x80x9cspeedxe2x80x9d (maximum comfortable velocity) at which a particular horse can both run and still breathe sufficiently and thereby utilize such as a predictor of potential racing performance of the horse.
The present invention provides a method for predicting racing performance in a horse, e.g., a Thoroughbred race horse, comprising measuring expiratory and/or inspiratory times for a subject horse during exercise and relating such information to anatomy, front leg stance times and/or front leg stance distances and/or to speed (velocity) to determine the animal""s potential to sustain a superior rate of ground coverage for a desired amount of time and identify a maximum comfortable velocity for the animal. A presently preferred embodiment of the methods of the invention comprises predicting performance via identification of expiratory time determined directly from the analysis of recorded respiratory sound from the exercising animal. The inspiratory and expiratory times can be measured directly from analysis of the amplitude envelope of the recorded sound using spectrogram analysis or other suitable computer software. A maximum comfortable velocity can be determined from expiratory time and velocity and performance predictions made.
The invention also provides a device for attachment to the head of a horse to enable recording of respiratory sounds in the intensely exercising animal, e.g., in a breezing Thoroughbred racehorse. In the presently preferred embodiment, the device is a lightweight blinkers-like hood which is placed on the subject horses head. The device is made to fit snugly over the face and comprises a pouch or closeable pocket located on the front of the hood for removable placement of a recording device. A thin shaft extends distally down the midline and over the bridge of the nose to a point just slightly in front of the tip of the horse""s nose to carry the recording microphone.